Modding French 7800 to composite?

I recently bought French 7800. Unfortunately the picture quality via scart is really bad. While playing 2600 games there is ugly thick "scanlines" and 7800 don't look good either. It seems my that the rgb board is either broken or just bad. I attached a photo where you can see the horizontal lines.

So I'm planning to mod the console, so I can use composite.

The problem is that the motherboard is slightly different than pal version.

Scart gives RGB + Composite + audio.Some pins are the RGB ones, others are the composite ones.TV set looks first for the RGB signal, then drops to composite signal if RGB is not found. So, removing/pushing RGB pins from the Scart forces composite output.(There are also cheap "dongles" with Scart-in --> RCA-out).

From the pic I would say you have a shielding issue, maybe a bad cable. Does the cable look original?

Mitch

The cable is original and I've started to mod the console to composite and it shows the same problems as via scart. The problem with the mod at the moment is that the motherboard is different than the pal version, so I only managed to get black and white picture out of the motherboard. I suspect that I need to take out and add some resistors to the motherboard because of the differences between pal and secam versions.

Scart gives RGB + Composite + audio.Some pins are the RGB ones, others are the composite ones.TV set looks first for the RGB signal, then drops to composite signal if RGB is not found. So, removing/pushing RGB pins from the Scart forces composite output.(There are also cheap "dongles" with Scart-in --> RCA-out).

Thanks for the advice, but in this case the picture quality from the rgb board (or the console itself) gives a really bad picture quality via rgb and via composite (I've started to mod the console to composite, but it only shows black and white colors). I mentioned in a new post that I suspect that I need to remove and insert some resistors, so I might get colors, and to get rid of the vertical lines. I'm also suspecting that the secam 7800 might also be broken.

Can you post a pic of the system board?By the way, there isn't a secam 7800, only PAL and NTSC.

Mitch

Ok, good to know! I didn't know about that fact it isn't secam.

The pictures aren't that great, but I'll take a better shot later. I've removed the rgb daughterboard and some of the resistors that have to be removed for the composite mod. The thing is that I need to know which resistors I have attach to the motherboard, as some of them are missing in the French version.

Does anyone know what resistors I need to these areas which I have marked?

The French 7800 does not have them. I've removed some resistors needed to the composite mod. When compared to the regular pal version, it seems to have resistors in places which the French does not have. I guess I need them to complete the composite mod, because otherwise the picture is black and white. It might also affect the picture quality.

The other picture is from one of the mod tutorials I've found via Internet.

Does anyone know anything about the resistor/transistor I've marked on the picture. You can find it on the regular pal motherboard, but not on the French version. I'm still wondering how to make the composite mod, I just have to know what parts I have to buy.

I'm starting to think that maybe I should just buy a 2600 Junior to play my Pal 2600 games, and play ntsc 7800 and 2600 on my ntsc 7800 because the French 7800 is either broken or just bad. Too bad for me, because the French 7800 wasn't cheap. Too bad about the really bad picture quality. I thought that having a scart version would have been the best version out there

Have you tried a different TV? My French 7800 looks terrible on my LCD that displays s-video 8 bit consoles really nicely.Looks fine on my Sony CRT though.On my big plasma screen it displays terribly with the genuine peritel cable, but perfectly fine on the cable I made myself for my ST.

Yes, I've tried three different types of tv's: oled with framemeister, lcd and crt tv. Most surprising was the crt, as it looked as horrible as on modern tv sets.